1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device which can obtain uniform luminance and minimized light leakage.
2. Description of the Related Art
In general, a liquid crystal display (LCD) device is a device that displays a desired image by adjusting optical transmittance of liquid crystal cells arranged in a matrix shape according to picture signal information. The liquid crystal display device uses light irradiated from a backlight unit to implement an image on a liquid crystal panel.
As shown in FIG. 1, such liquid crystal display device 1 includes a liquid crystal panel 2 on which liquid crystal cells of a pixel unit are arranged in a matrix shape, a backlight unit 3 uniformly supplying light to the liquid crystal panel 2, a bottom cover 4 for receiving the backlight unit 3, and a top cover 5 coupled to the bottom cover 4 for receiving the liquid crystal panel 2 and the backlight unit 3 therein. And, the backlight unit 3 includes a light guide plate 3a disposed at a rear surface of the liquid crystal panel 2, a lamp 3b disposed along one side surface (incident plane, entrance surface) of the light guide plate 3a, a lamp housing 3c covering the lamp 3b, optical sheets 3d disposed between the light guide plate 3a and the liquid crystal panel 2, and a reflecting plate 3e disposed between the bottom cover 4 and the light guide plate 3a. Here, the reflecting plate 3e is mounted at a lower surface portion of the bottom cover 4, and is spaced from a rear surface of the light guide plate 3a with a certain distance therebetween.
Light from the lamp 3d is incident onto the one side surface (incident plane, entrance surface) of the light guide plate 3a, and the incident light is reflected to the rear surface of the light guide plate 3a, thereby being irradiated onto the liquid crystal panel 2.
However, some of light emitted from the lamp 3d may not be incident onto the incident plane (entrance surface) of the light guide plate 3a, but be incident onto the spaced area between the light guide plate 3a and the reflecting plate 3e. Such undesirable light is reflected to the reflecting plate 3e again, and then is irradiated onto the liquid crystal panel 2, thereby not being considered as light that is uniformly induced by the light guide plate 3a. Such uncontrolled light causes non-uniform luminance of the liquid crystal panel 2 and light leakage.